Concepts
About images
An image is a template of a VM (Virtual Machine) that contains at least an OS (Operating System) and possibly other software applications and configurations, such as block device mappings.
Images let you create VM with a predefined configuration and the software applications you need, without having to install these applications on each VM you create for the same use case. This lets you save time and ensure the consistency of your VM configurations.
It is important to note that images can be created from existing VM or imported from image files. You can also create your own custom images according to your needs.
General information
An image is used as a template to create VM based on a block storage volume as the root volume. An image provides at least a Linux operating system and can include software applications or copies of other block storage volumes.
An image also provides a configuration for the VM attributes, such as DisableApiTermination.
Images can be created in two ways:
- from a snapshot of a volume
- in this case, the snapshot is used to create the root volume of the VM that are created from the image.
- from a VM
- a snapshot of the VM system volume is created. This snapshot is used to create the image.
- the image is then used to create the system volume of the new VM.
- if the source VM has other block storage volumes attached, snapshots of these volumes are also created.
- the new VM are created with a copy of all these attached volumes. In short, each volume of the source VM is copied and attached to the new VM created from the image.
Image types
There are two types of images in Numspot:
Official images
Official images are images provided by Numspot, based on open source Linux distributions (Debian, Ubuntu, AlmaLinux, RockyLinux). They are ready to use and include the latest security updates.
To see the complete list of available official images, see Official images reference.
Numspot guarantees that the content of the official images is up to date. However, once a VM is launched from one of these images, it is your responsibility to update your environments.
Private images
Private images are images that you have created from a VM or a snapshot, or imported from an export stored on an object storage bucket. By default, any image you create is private.
To share a private image with other spaces or organizations, you can use the image export feature to an object storage bucket, then import it from this bucket into the target space.
Numspot cannot guarantee the correct operation of VM created from unofficial sources.
Architecture
Official images and private images are available in 64-bit (x86_64) architecture only.
- We strongly recommend that you use only official images to create your VM. Images from other sources may contain a built-in root password or SSH (Secure Shell) key, which are not removed when you create a new VM and add your key pair. In this case, you must check the ~/.ssh/authorized_keys file and keep only the last entry that corresponds to the public part of your key pair.